JP2011205753A - Electric motor, and manufacturing method of rotor of electric motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the wobbling of a permanent magnet with a simpler constitution.SOLUTION: Side faces 29a at internal peripheral sides of ends 28a, 28b of both sides of the permanent magnet 28 of a rotor core 24 are inclined at angles θa smaller than 90° with respect to the axial face 24a of the rotor core 24, a radial width Lw is narrowed toward the outside by setting the side face 29b of the external peripheral side at 90° with respect to the end face 24a of the rotor core 24, and a penetration hole 26 is formed so as to match the permanent magnet 28. By this, the wobbling of the permanent magnet 28 can be suppressed with the simpler constitution as compared with the case that there is arranged a member for fixing the permanent magnet 28 into the penetration hole 26.

Description

  The present invention relates to an electric motor and a method for manufacturing a rotor of the electric motor.

  Conventionally, as an electric motor of this type, in an electric motor including a rotor in which a permanent magnet is stored in an internal permanent magnet storage space and end plates mounted on both end surfaces of the rotor in the rotation axis direction, The thing which provided the protrusion which presses the edge part of the outer peripheral side of a permanent magnet is proposed (for example, refer patent document 1). In this electric motor, by pressing the end of the permanent magnet with the protrusion of the end plate, it is possible to prevent the permanent magnet from rattling in the permanent magnet storage space as the rotor rotates.

Japanese Patent Laid-Open No. 8-88963

  However, in the above-described electric motor, since it is necessary to prepare an end plate separately from the rotor in order to suppress rattling of the permanent magnet, the number of parts increases and the electric motor becomes large. As a method of suppressing the backlash of the permanent magnet while suppressing the motor from becoming large, the permanent magnet is sealed in the permanent magnet housing space by pouring resin with the permanent magnet placed in the permanent magnet housing space. In this case, it becomes difficult to take out the permanent magnet from the rotor and reuse it.

  The main purpose of the method of manufacturing an electric motor and an electric motor rotor of the present invention is to suppress rattling of a permanent magnet with a simpler configuration.

  The electric motor and the method for manufacturing the electric motor rotor of the present invention employ the following means in order to achieve the main object described above.

The electric motor of the present invention is
An electric motor comprising a rotor in which a permanent magnet is housed in a magnet housing portion of a substantially cylindrical rotor core,
The permanent magnet is formed such that at least one end portion of both end portions in the longitudinal direction becomes gradually thinner toward the outside in the longitudinal direction,
The magnet storage part is formed in a shape that matches the permanent magnet.

  In the electric motor of the present invention, since the magnet housing portion is formed in a shape that matches the permanent magnet, the movement of the permanent magnet can be restricted by the magnet housing portion, and the member for fixing the permanent magnet in the magnet housing portion Can be prevented with a simpler configuration without separately preparing the magnet.

  In such an electric motor of the present invention, the permanent magnet is formed such that both end portions in the longitudinal direction become gradually thinner toward the outside in the longitudinal direction, and the rotor core is formed so as to be divided into a plurality of portions in the longitudinal direction. It can also be. In this case, the permanent magnet can be easily taken out as compared with the case where the permanent magnet is sealed by pouring resin into the storage portion. In this case, the permanent magnet is formed such that the inner peripheral surface of the rotor core at both ends is inclined with respect to the end surface in the axial direction of the rotor core, or the permanent magnet is The outer peripheral surface of the rotor core may be formed so as to be inclined with respect to the axial end surface of the rotor core.

  In the electric motor of the present invention, the rotor core may be formed by laminating a plurality of core plates formed in an annular shape from electromagnetic steel plates.

The method for manufacturing the rotor of the electric motor of the present invention is as follows.
A method of manufacturing a rotor for an electric motor,
The first insertion portion from one end to the first length of both ends of the permanent magnet formed such that both end portions in the longitudinal direction become gradually smaller toward the outside in the longitudinal direction has a substantially cylindrical shape and a shaft A first core formed with a first magnet storage portion formed so that the length in the direction is substantially the same as the length of the first insertion portion of the permanent magnet and aligned with the first insertion portion of the permanent magnet Inserted into the first magnet housing part of the member,
With the first insertion portion of the permanent magnet inserted into the first magnet housing portion of the first core member, the remaining second insertion portion excluding the first insertion portion of the permanent magnet has a substantially cylindrical shape. And a second shape that is formed to be substantially the same as the axial length of the permanent magnet when the axial length is combined with the first core member and matches the second insertion portion of the permanent magnet. Inserting the second magnet housing part of the second core member formed with the magnet housing part to manufacture the rotor;
This is the gist.

  In the method for manufacturing a rotor of an electric motor according to the present invention, the first end from one end to the first length of both ends of the permanent magnet formed such that both end portions in the longitudinal direction gradually decrease toward the outside in the longitudinal direction. The first insertion portion has a substantially cylindrical shape and is formed so that the length in the axial direction is substantially the same as the length of the first insertion portion of the permanent magnet, and is aligned with the first insertion portion of the permanent magnet. The first permanent magnet is inserted into the first magnet housing part of the first core member formed with the magnet housing part and the first insertion part of the permanent magnet is inserted into the first magnet housing part of the first core member. The remaining second insertion portion excluding the insertion portion is formed in a substantially cylindrical shape so that the axial length is substantially the same as the axial length of the permanent magnet when combined with the first core member. A second magnet storage portion having a shape matching the second insertion portion of the permanent magnet is formed. It is inserted into the second magnet housing section of the second core member, to produce the rotor. Thereby, the rotor of the electric motor which can suppress the backlash of a permanent magnet with a simpler structure can be manufactured.

It is a block diagram which shows the outline of a structure of the motor 10 as one Example of this invention. It is an external view which shows the outline of an external appearance when the rotor 20 is seen from the A direction of FIG. It is a cross-sectional schematic diagram which shows the outline of the cross section in the BB line of FIG. FIG. 4 is an enlarged view of a region C in FIG. 3. 5 is a process diagram illustrating an example of a manufacturing process of the rotor 20. FIG. FIG. 5 is an explanatory diagram showing a state of a process of inserting a core member 30 into a permanent magnet 28. FIG. 6 is an explanatory diagram showing a state of a process of inserting a core member 32 into the permanent magnet 28. It is a cross-sectional schematic diagram which shows the outline of a structure of the rotor 120 of a modification. It is a cross-sectional schematic diagram which shows the outline of a structure of the rotor 220 of a modification. It is a cross-sectional schematic diagram which shows the outline of a structure of the rotor 320 of a modification. FIG. 10 is a schematic cross-sectional view illustrating a schematic configuration of a rotor 420 according to a modification.

  Next, the form for implementing this invention is demonstrated using an Example.

  FIG. 1 is a block diagram showing an outline of the configuration of a motor 10 as an embodiment of the present invention. The motor 10 is configured as a permanent magnet synchronous motor (PM motor), and includes a stator 12 around which a three-phase coil is wound, and a rotor 20 fixed to a rotor shaft 14 as a rotating shaft.

  2 is an external view showing an outline of the appearance when the rotor 20 is viewed from the direction A in FIG. 1, FIG. 3 is a schematic cross-sectional view showing an outline of a cross section taken along line BB in FIG. 2, and FIG. FIG. 4 is an enlarged view of a region C in FIG. 3. As shown in the drawing, the rotor 20 is formed by laminating a plurality of core plates 22 made of a magnetic material such as iron and having a predetermined thickness (for example, 0.3 mm, 0.5 mm, 1.0 mm, etc.). Thus, the axial direction is accommodated in a rotor core 24 having a length L1 (for example, 40 mm, 50 mm, 60 mm, etc.) and a plurality of through holes 26 (16 in the embodiment) formed so as to penetrate the rotor core 24 in the axial direction. And a plurality of permanent magnets 28 (16 in the embodiment).

  The permanent magnet 28 is formed such that the radial width Lw changes in the axial direction. As for the end portions 28a and 28b from the both ends of the permanent magnet 28 to the length L2 (for example, 1 mm, 2 mm, 3 mm, etc.), the inner peripheral side surface 29a is connected to the end surface in the axial direction of the rotor core 24 as shown in FIG. By tilting at an angle θa smaller than 90 degrees with respect to 24a (for example, 30 degrees, 45 degrees, 60 degrees, etc.) and setting the outer side surface 29b to 90 degrees with respect to the end surface 24a of the rotor core 24, the radial direction The width Lw is formed so as to decrease toward the outside. And the site | part between the edge part 28a and the edge part 28b is formed so that the radial width Lw may become substantially constant. The through hole 26 is formed so that the radial width becomes smaller toward the outer side so as to be aligned with the permanent magnet 28 thus formed. In this way, the end portions 28a and 28b of the permanent magnet 28 are formed so that the radial width Lw decreases toward the outside, and the through hole 26 is formed in a shape that matches the permanent magnet 28. Since the inner wall is in close contact with the permanent magnet 28, it is possible to suppress the backlash of the permanent magnet 28 and the dropout to the outside in the axial direction. According to such a configuration, there is no need to separately provide a fixing member for fixing the permanent magnet 28. Therefore, the permanent magnet 28 has a backlash and an axial direction with a simpler configuration as compared with a configuration in which a fixing member is separately provided. It is possible to suppress falling off. Further, since the inner peripheral side surface 29a is formed so as to be inclined with respect to the end surface 24a of the rotor core 24, the permanent magnet 28, the stator 12 and the stator 12 are compared with those in which the outer peripheral side surface 29b is inclined with respect to the end surface 24a. The shape of the magnetic flux between the two can be improved. Further, since the rotor core 24 is formed by stacking a plurality of core plates 22, the rotor core 24 is axially separated by separating the core plates 22 one by one or by separating the plurality of core plates 22 as a set. Can be divided. Thereby, the permanent magnet 28 can be easily taken out as compared with the case where the permanent magnet is sealed by pouring resin into the through hole.

  Then, the manufacturing method of the rotor 20 comprised in this way is demonstrated. FIG. 5 is a process diagram showing an example of the manufacturing process of the rotor 20. First, as shown in FIG. 6, the rotor 20 is manufactured by a permanent magnet 28 formed in a shape in which both end portions in the longitudinal direction gradually narrow toward the outside in the longitudinal direction, and one core plate 22 of the rotor core 24. The insertion portion 28c has a length L3 (for example, 20 mm, 25 mm, 30 mm, etc.) that is smaller than the length L1 of the permanent magnet 28 and is laminated from the end of the permanent magnet 28 to the length L3. The core member 30 in which the through hole 30a having a shape matching the above is formed is prepared, and the insertion portion 28c of the permanent magnet 28 is inserted into the through hole 30a of the core member 30 (step S100).

  Subsequently, as shown in FIG. 7, the remaining core plate 22 is laminated so that the axial direction becomes the length L1 when combined with the core member 30 and the insertion portion 28c of the permanent magnet 28 is excluded. The core member 32 in which the through hole 32a that matches the remaining insertion portion 28d is prepared, and the through hole of the core member 32 is inserted in the state where the insertion portion 28c of the permanent magnet 28 is inserted into the through hole 30a of the core member 30. The rotor 20 is manufactured by inserting the insertion portion 28d of the permanent magnet 28 into 32a (step S110). Thereby, the rotor 20 of the motor 10 that can suppress the backlash of the permanent magnet 28 and the axial movement of the permanent magnet 28 to the outside in the axial direction can be manufactured with a simpler configuration.

  According to the motor 10 of the embodiment described above, the end portions 28a, 28b of the permanent magnet 28 are formed so that the radial width Lw decreases toward the outside, and the through hole 26 is formed to match the permanent magnet 28. Since it formed, the backlash of the permanent magnet 28 can be suppressed with a simpler configuration. The core member 30 is formed with a permanent magnet 28 formed in a shape in which both end portions in the longitudinal direction are gradually narrowed toward the outside in the longitudinal direction, and a through hole 30a having a shape matching the insertion portion 28c of the permanent magnet 28. And the permanent magnet 28 is inserted into the through hole 30a of the core member 30, and when combined with the core member 30, the axial direction has a length L1 and the through hole has a shape that matches the insertion portion 28d of the permanent magnet 28. A core member 32 formed with 32 a is prepared, and the insertion portion 28 d of the permanent magnet 28 is inserted into the through hole 32 a of the core member 32 in a state where the insertion portion 28 c of the permanent magnet 28 is inserted into the through hole 30 a of the core member 30. Thus, the rotor 20 of the motor 10 that can suppress the backlash of the permanent magnet 28 and the axial direction of the permanent magnet 28 can be manufactured with a simpler configuration.

  In the motor 10 of the embodiment, the end portions 28a and 28b of the permanent magnet 28 are inclined with respect to the end surface 24a of the rotor core 24 at the inner circumferential side surface 29a at an angle θa and the outer peripheral side surface 29b is tilted with respect to the end surface 24a. Although the shape is substantially perpendicular, the end portions 28a and 28b of the permanent magnet 28 may be shaped so that the radial width Lw decreases toward the outside. Therefore, the rotor 120 of the modified example of FIG. As illustrated, the inner peripheral side surface 29a of the end portions 28a, 28b of the permanent magnet 28 is substantially perpendicular to the end surface 24a, and the outer peripheral side surface 29b is inclined with respect to the end surface 24a at an angle θa. In addition, as illustrated in the rotor 220 of the modified example of FIG. 9, the inner side surface 29a and the outer side surface 29b of the end portions 28a and 28b of the permanent magnet 28 are angled with respect to the end surface 24a. The shape may be inclined with a degree θa.

  In the motor 10 of the embodiment, both the end portions 28a and 28b of the permanent magnet 28 are formed so that the radial width Lw decreases toward the outside. However, the rotor 320 of the modified example of FIG. 10 is exemplified. As described above, one end of the end portions 28a and 28b of the permanent magnet 328 is formed so that the radial width Lw is reduced toward the outside, and the other end portion is provided with the radial width Lw toward the outside. The through hole 326 may be formed to have a constant width and have a shape matching the permanent magnet 328. In this case, as shown in the drawing, the end face on the end side where the width Lw in the radial direction of the rotor core 24 is constant toward the outside is annular so as to cover the permanent magnet 28 exposed on the end face. The plate member 334 may be provided. By so doing, the plate-like member 334 can suppress the backlash of the permanent magnet 28 and can also prevent the permanent magnet 28 from falling off from the end surface.

  In the motor 10 of the embodiment, the permanent magnet 28 is accommodated in the through hole 26 of the rotor core 24. However, the present invention is not limited to the case where the permanent magnet 28 is accommodated in the through hole 26, and the modified example of FIG. As illustrated in the rotor 420, a space 426 having a shape that is not opened in the axial direction and is aligned with the permanent magnet 28 may be provided in the rotor core 24, and the permanent magnet 28 may be accommodated in the space 426.

  In the motor 10 of the embodiment, the rotor core 24 is configured by laminating the core plate 22, but the rotor core 24 may be configured by a single substantially cylindrical member.

  The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problems will be described. In the embodiment, the permanent magnet 28 corresponds to a “permanent magnet”, and the through hole 26 corresponds to a “magnet storage portion”. Here, the “permanent magnet” is not limited to the permanent magnet 28, and is formed such that at least one end portion of both end portions in the longitudinal direction becomes gradually narrower toward the outside in the longitudinal direction. Anything can be used. The “magnet storage portion” is not limited to the through hole 26, but is formed in a shape that matches the permanent magnet, such as a space 426 that is not opened in the axial direction in the rotor core 24 and matches the permanent magnet 28. It does not matter as long as it is made. The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problem is the same as that of the embodiment described in the column of means for solving the problem. Therefore, the elements of the invention described in the column of means for solving the problems are not limited. That is, the interpretation of the invention described in the column of means for solving the problems should be made based on the description of the column, and the examples are those of the invention described in the column of means for solving the problems. It is only a specific example.

  As mentioned above, although the form for implementing this invention was demonstrated using the Example, this invention is not limited at all to such an Example, In the range which does not deviate from the summary of this invention, it is with various forms. Of course, it can be implemented.

  The present invention can be used in the manufacturing industry of electric motors and electric motor rotors.

  DESCRIPTION OF SYMBOLS 10 Motor, 12 Stator, 14 Rotor shaft, 20, 120, 220, 320, 420 Rotor, 22 Core plate, 24 Rotor core, 24a End surface, 26, 30a, 32a, 326 Through hole, 28, 328 Permanent magnet, 28a, 28b End part, 28c, 28d Insertion part, 29a, 29b Side surface, 30, 32 Core member, 334 Plate member, 426 Space.

Claims (6)

An electric motor comprising a rotor in which a permanent magnet is housed in a magnet housing portion of a substantially cylindrical rotor core,
The permanent magnet is formed such that at least one end portion of both end portions in the longitudinal direction becomes gradually thinner toward the outside in the longitudinal direction,
The said magnet accommodating part is formed in the shape matched with the said permanent magnet. The electric motor according to claim 1,
The permanent magnet is formed such that both end portions in the longitudinal direction become gradually thinner toward the outside in the longitudinal direction,
The rotor core is formed so as to be divided into a plurality of parts in the longitudinal direction. The electric motor according to claim 2,
The said permanent magnet is formed so that the surface of the inner peripheral side of the said rotor core of the said both ends may incline with respect to the end surface of the axial direction of the said rotor core. The electric motor according to claim 2 or 3,
The said permanent magnet is formed so that the outer peripheral surface of the said rotor core of the said both ends inclines with respect to the end surface of the axial direction of the said rotor core. The electric motor according to any one of claims 1 to 4,
The rotor core is an electric motor in which a plurality of core plates formed in an annular shape by electromagnetic steel plates are laminated. A method of manufacturing a rotor for an electric motor,
The first insertion portion from one end to the first length of both ends of the permanent magnet formed such that both end portions in the longitudinal direction become gradually smaller toward the outside in the longitudinal direction has a substantially cylindrical shape and a shaft A first core formed with a first magnet storage portion formed so that the length in the direction is substantially the same as the length of the first insertion portion of the permanent magnet and aligned with the first insertion portion of the permanent magnet Inserted into the first magnet housing part of the member,
With the first insertion portion of the permanent magnet inserted into the first magnet housing portion of the first core member, the remaining second insertion portion excluding the first insertion portion of the permanent magnet has a substantially cylindrical shape. And a second shape that is formed to be substantially the same as the axial length of the permanent magnet when the axial length is combined with the first core member and matches the second insertion portion of the permanent magnet. Inserting the second magnet housing part of the second core member formed with the magnet housing part to manufacture the rotor;
A method for manufacturing a rotor of an electric motor.

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